Clariant has added a new oxygen-scavenging additive masterbatch to its MEVOPUR line of medical-grade materials and services for pharmaceutical packaging and medical devices. MEVOPUR ProTect is reportedly effective at limiting oxygen degradation of drugs and nutraceuticals stored in PET bottles, even in a transparent mono-layer construction.

“Just as in food and beverage packaging, PET is becoming more widely used but while food and beverages require a relatively short shelf life, pharmaceuticals often need to maintain their potency even when stored for a year or more. Although HDPE has been the material of choice, PET offers several advantages, including transparency, and the MEVOPUR ProTect additives help to combine transparency with long-term shelf-life. And, while recycling is not yet a major topic in pharma, PET is considered a highly recyclable material, and any oxygen barrier that does not require multiple layers is going to be an advantage,” notes Steve Duckworth, global head of marketing & business development for Clariant Healthcare Polymer Solutions.

Originally developed to overcome what Clariant describes as the “deficiencies of existing oxygen barrier systems used in food and beverage packaging,” the active molecules apparently showed very high performance in scavenging oxygen permeating through container walls, thereby reportedly maintaining extremely low levels of O2 over extended periods even in a mono-layer and refrigerated storage. Clariant reports that this makes it possible to meet the ‘>2 years’ shelf-life required in pharmaceutical packaging, even with low concentrations of the active ingredient compared to alternative products. In addition, the company says that tests have shown that PET pre-forms do not need special storage conditions, still maintaining activity after 3 months.

The protection offered by the oxygen scavenging system depends on a number of factors including packaging design, additive loading, and target oxygen levels over time. However, by way of illustration, Clariant testing of 500 ml monolayer PET bottles with 3.6% loading of the masterbatch concentrate was able to maintain oxygen levels below 1 ppm for more than 590 days, compared to just 22 days for untreated PET, and 63 days for a competitive oxygen scavenger.